DE1501101B2 - Device for generating cold and / or for liquefying gases - Google Patents

Description

The invention relates to a device for generating cold and / or for liquefying Gases, with a supply for a gaseous medium under high pressure, to which the High-pressure part of at least one countercurrent heat exchanger connects, in which the under high Pressurized gaseous medium cools to a temperature which is lower than that mentioned Pressure associated inversion temperature, furthermore with one at the outlet of the high pressure part the counterflow heat exchanger connected to the pressure reducing device containing at least one throttle element, as well as with at least one adjoining container in which the medium is in thermal contact with lower pressure can be brought to a point to be cooled or removed from the device in a liquid state, and with a line system through which the medium of lower pressure over the low pressure part the countercurrent heat exchanger is removed.

In known devices of the type according to the invention are to achieve the desired Pressure reduction Joule-Kelvin taps are used, in which the high-pressure medium increases significantly lower pressure is throttled. With the right choice of pressure and temperature, this takes place Throttling process a temperature decrease of the medium or a phase transition of part of the Medium or both processes occur in combination. The low pressure medium can then with a cooling object or a medium to be cooled are brought into thermal contact. in the In the event of a phase transition, part of the resulting liquid can be discharged from the device will. The resulting low-pressure steam is then discharged to the environment or to a Recirculated compressor, which supplies the high pressure medium.

A cooling device is also known in which a turbine and an ejector are connected in series are. However, a Joule-Kelvin effect occurs. Furthermore, in this known device is the

ίο The suction pressure of the compressor is the same as that in the cold room prevailing pressure. There is therefore no pressure difference between the device in this device Cooling space and the medium suction line, so that pressure energy of the high pressure medium is not used can be used to compress steam from the container at the lowest pressure.

To achieve very low temperatures it is necessary to throttle down to very low pressures. Is used as a medium z. B. Helium is used, and a temperature of 4.2 ° K should be reached, so must be throttled to about 1 ata, for 3.6 ° K to about 0.5 ata. For even lower temperatures must be throttled to even lower pressures. This means that in a closed system the compressor can be very large and the low-pressure side of the heat exchanger has a low flow resistance must have. As a result, the known devices are complex, large and expensive. Furthermore, if it is an open system, in which the high-pressure medium is any one Taken from the source and the low-pressure medium after heat exchange with the one to be cooled Object is discharged into the open, and if cold at a sub-atmospheric pressure corresponding Temperatures are to be delivered, the device can not be self-blowing. It Additional precautions are therefore necessary in order to discharge the low-pressure medium from the device.

Another disadvantage of the known devices is that the pressure energy of the high-pressure medium is readily dissipated in the Joule-Kelvin taps, which therefore entails losses.
The invention aims to remedy these disadvantages, and is characterized in that the pressure reducing device contains at least one ejector to which at least part of the still unthrottled, high pressure cooled medium is fed and whose suction side is connected to the lower pressure container, while the discharge of the Ejector is connected to the pipe system through which the medium of lower pressure is discharged.

In this context, an ejector should be understood to mean a device in which the potential energy of a (primary) high-pressure medium completely or partially converted into kinetic energy which is used at least partially to increase the pressure of a second (secondary) medium will.

According to the invention, the energy of the high pressure medium supplied to the ejector becomes at least partially used to suck the steam out of the low-pressure container and then to the in the Line system for discharging the medium to bring lower pressure prevailing pressure. The refrigeration can then be delivered at a pressure which is lower than the discharge pressure. this has

the advantage that in an open system, the device can be self-blowing and that the Cold at a lower pressure than the blow-off pressure is supplied.

If, as in a further advantageous embodiment of the invention, a compressor is present is, whose drain is connected to the supply of high pressure medium and whose inlet is connected to the discharge of the Connect the medium with a lower pressure, the pressure ratio at the compressor can be considerably lower than with known devices of this type.

The difference between the known device and the device according to the invention is thus that the pressure energy of the medium supplied to the ejector is not readily is dissipated, but also used to pump the steam out of the lower pressure container until the suction pressure of the compressor or the discharge pressure of the medium is reached. the The device obtained in this way has a higher efficiency and a significantly more favorable pressure ratio in the heat exchanger and in the compressor, it is also cheaper and considerably smaller.

Another advantageous embodiment of the invention is characterized in that one or several parallel ejectors are provided, the (their) supply side (s) are attached to the high pressure part the heat exchanger (s) and its (their) discharge side (s) are connected to a collecting tank connects (connect), whose vapor space with the pipe discharge system for the medium is lower Pressure is in connection, which device has a further container by a Line with a throttle member with the collecting container, preferably with the liquid space this Container is in connection, the vapor space of the further container with the suction side of the Ejector (the ejectors) is connected. In this device, the further container can thus a subject to lower pressure than the collecting container, so that the cold is delivered at a lower temperature wrid. The steam is sucked out of the further container through the ejector and onto the one in the collecting container prevailing pressure brought.

Another favorable embodiment of the device according to the invention is characterized in that that it has two or more ejectors, each of which is supplied with the high pressure part the heat exchanger (the heat exchanger) and the discharge side are connected to a container, which containers have lower pressures in sequence during operation and through lines with throttling elements are laid in series with one another, the high pressure sides of these lines preferably in the liquid spaces of the containers concerned open out and the container with the lowest pressure is through a line with a throttle member with a further container in connection, in which a still lower pressure prevails throughout the vapor spaces of all vessels, with the exception of that The vapor space of the container with the highest pressure is connected to the suction side of an ejector, the discharge side of which is connected to a container with a higher pressure and the vapor space of the container with the highest pressure with the pipeline evacuation system of the medium lower Pressure is related. In this embodiment, a number of containers with ver different pressures available, so that there is the possibility of this device cold at different Temperatures.

In a further, favorable embodiment, there are a number of ejectors placed in a row, the first of these ejectors having the supply side to the last heat exchanger and the last ejector with its discharge is connected to the collecting container, the vapor space of which with the ίο Line removal system for the medium lower pressure is connected, furthermore at least Another container is provided, which container in sequence by liquid lines with throttle members are connected to one another, the first further container connected to the collecting container and the vapor space of each of the further containers with the suction side of one or more of the Ejectors is in communication. In this way there is again a number lower in order Containers exhibiting pressures, which therefore also have a decreasing temperature in sequence. This enables cold to be taken from the device at different temperatures. It is on possible, e.g. a medium in sequence with the medium in the various containers in thermal To bring contact, so that this medium is cooled to different temperatures.

In a further embodiment, one or more throttle elements are parallel to the ejectors placed that part of the medium emerging from the high pressure part of the heat exchanger (s) this throttle element (s) passes through and then into the collecting container and / or into one of the other Container.

Another advantageous embodiment of the device according to the invention is characterized in that that it has only one container, which is connected to the high pressure part of the heat exchanger (s) through a throttle element is in connection, which device further includes an ejector, the supply side of which also to the high pressure part of the heat exchanger (s) and its discharge to the pipe discharge system of the medium lower pressure connect, whereby the suction side of the ejector is connected to the vapor space of the container. Even here the pressure in the container is lower than that at which the medium is discharged.

In an advantageous development of the device according to the invention, each of the connecting lines contains between the suction side of each of the ejectors and a vapor space of a further container one or more heat exchangers in which the one flowing to the suction side of the ejectors Medium exchanges heat with the medium of higher pressure. The efficiency of the device is increased this way.

In a further advantageous embodiment of the device according to the invention, there is a control element provided that one or more of the throttle elements in the lines between the liquid spaces the container concerned regulates depending on the liquid level in these containers. This control element can, for. B. be formed by a float, which determines the position of the throttle member in question conditional.

Furthermore, in a further, advantageous embodiment, one or more of the ejectors can be regulated, so that the high pressure medium flow through

se (n) ejector (s) can be regulated. In this way the device can be adapted to changing circumstances adjust.

Another favorable embodiment of the device according to the invention, which is particularly good for Generating cold at very low temperatures is characterized in that a machine for generating cold at low temperatures, one or more with a working medium filled compression and one or more expansion spaces Volume, which rooms are connected to each other and different in operation have medium temperatures, the connections between these rooms each one or more Contain regenerators and the medium flowing to the ejector (s) or throttle element (s) is in thermal contact with the working medium in the expansion space (s).

In a further advantageous embodiment, the machine is used to generate cold at low temperatures Temperatures, possibly together with a further compression member, also as a compressor for the medium flowing to the ejector (s) or the throttle element (s), which machine is provided with a drain and an inlet valve connected to the heat exchanger (s) connect so that the medium flows to the ejector (s) or the throttle element (s) through the the pipe system adjoining the steam chamber flows into it.

It should also be noted that for the type, control, etc. of the device according to the invention all techniques customary in compression refrigeration machines can be considered.

This results in an extremely favorable type of device for generating cold.

The invention is explained in more detail with reference to the drawing.

In the F i g. 1 a and 1 b are two known devices for generating cold shown schematically.

The F i g. 2 to 7 schematically show a number of embodiments of the device for generating of cold, each containing one or more ejectors;

F i g. 8 schematically shows a device for generating cold which, in addition to an ejector, has a Contains cold gas cooling machine for cooling the compressed working medium;

F i g. 9 schematically shows a device for generating cold, which includes an ejector and in which a cold gas cooling machine is available, which acts as a compressor and as a cooling unit for the relaxation Medium is effective.

F i g. FIG. 1 a shows a known device for generating cold which contains a compressor 1. Of the Outlet 2 of the compressor connects to the high pressure part 3 of a heat exchanger. That in that Heat exchanger cooled medium is throttled in a throttle valve 4, which is attached to a collecting container 5 connects. A quantity of heat can be supplied to this container 5, for example by the to cooling medium is passed through a helix 6. Instead of the medium passed through a helix can an object to be cooled with the container 5 and the liquid contained therein in thermal Be brought into contact. The existing steam in the container 5 is through the low pressure part 7 of the heat exchanger is fed to the inlet 8 of the compressor 1. The temperature at which the Cold is supplied (temperature of the liquid in container 5) depends on the pressure in this container from, the lower the pressure, the lower the temperature. If helium is used as a working medium is, at a pressure of about 1 ata in the container 5, the temperature is 4.2 ° K. It is often desirable

ίο to reach even lower temperatures. this can be achieved in that the pressure in the container 5 is chosen to be lower. At a pressure of 0.5 ata occurs a temperature of 3.6 ° K, etc. At these low pressures in the container 5 has the gas flowing back through the part 7 of the heat exchanger has a particularly large volume, so that Heat exchangers must have a large passage in order to achieve a low flow resistance reach. Since this is a closed system

ao stem, the compressor must be made very large because of the high pressure ratio.

An improvement on the known type described above is illustrated in Fig. Ib. The device contains a compressor 1, the outlet 2 of which is connected to the high pressure part 3 of a heat exchanger connects. A throttle valve 4 is used to throttle the medium. The throttled medium is collected in a container 9 in which a medium pressure prevails. The steam room of the Container 9 stands through part 10 of the heat exchanger with inlet 8 of compressor 1 in Link. The container 9 stands through a line 11 with a throttle member 12 with a container 5 lower pressure. A coil 6 to be cooled is arranged in this container. The vapor space of the container 5 closes through the part 7 of the heat exchanger to the environment at. In this device is thus gradually throttled, whereby the efficiency is favored.

Since the line 7 opens into the open air, the pressure in the container 5 cannot be lower than atmospheric Be pressure. The vapor developed in the container 5 is blown off and must in some way brought back to the desired pressure.

Especially if the cold is to be supplied at progressively lower temperatures, this still requires a very complicated heat exchanger and a large compressor.
The devices according to the invention shown in the figures to be described below eliminate the disadvantages of the known devices described above while maintaining all the advantages.

F i g. 2 shows a device with a compressor 1. The outlet 2 of this compressor closes to the high pressure part 3 of a heat exchanger. This part 3 of the heat exchanger follows the supply side 20 of an ejector 21. The discharge 22 of the ejector 21 is provided with a collecting container 23 tied together. The vapor space of the container 23 is through the part 7 of the heat exchanger with the Inlet 8 of the compressor in connection. The collecting container 23 is through a line 24 with a Throttle member 25 is connected to a further container 26. The vapor space of the container 26 is through a line 27 with heat exchangers 110 and 111 is connected to the suction side 28 of the ejector 21. A helix 29 is arranged in the container 26,

409 518/4

through which the medium to be cooled can be passed. Furthermore, a control member 30 is provided that the throttle element 25 as a function of the liquid level in the containers 23 and / or 26 regulates.

If necessary, the ejector can be provided with a control element 120. By changing the Position of the member 120, the high pressure medium flow passing through the ejectors can be regulated.

The mode of operation of this device is as follows: The compressor 1 compresses a medium, e.g. B. helium, to a pressure p _v. This high-pressure medium is cooled by heat exchange in the heat exchanger 3 and then fed to the ejector. In this ejector, the medium experiences a pressure reduction, with the potential energy being partially converted into kinetic energy; the latter is partially used to bring the high pressure medium back to the required pressure. The medium leaving the ejector at a pressure p ₂ is collected in a container 23. The steam with the pressure p ₂ can flow back into the compressor through part 7 of the heat exchanger. The developed liquid is throttled by the throttle element 25 to a pressure p ₃ , which corresponds to the temperature at which the cold is to be supplied. The steam in the container with the pressure p ₃ is sucked off by the ejector 21 and brought to the pressure p.- in the collecting container 23. Before the steam of the container 26 enters the ejector 21, it exchanges heat in the heat exchangers 110 and 111 with a medium of higher pressure. In the ejector 21, the energy of the high pressure medium (P ₁ ) is partly used for sucking off the container 26 and for pumping up the sucked off steam to a pressure p ₂ . The pressure p ₃ in the vessel 26, which corresponds to the desired low temperature, can here be considerably lower than the pressure p ₂ in the container 23. In this device, the compressor is thus _{effective between the pressures p., And P 1} , so that it can be structurally significantly simpler than in the known devices in which the compressor is effective _{between the pressures p., And P 1.}

Fig. 3 shows a variant of the device according to F i g. 2. This device contains three ejectors 31, 32 and 33 placed in series of the ejector 31 is connected to the part 3 of the heat exchanger. Next are the outlets 35, 37 and 39 of the ejectors 31, 32 and 33 with the supply sides 36 and 38 of the ejectors 32 and 33 and with, respectively the collecting vessel 40 connected. The device also contains three additional containers 41, 42 and 43, which are connected to one another by lines with throttle elements 44, 45 and 42.

The vapor spaces of the additional containers 41, 42 and 43 are through lines 49, 48, 47 with the heat exchangers 112, 113, 114, 115, 115, 117 contained therein with the suction sides 50, 51, 52 of the Ejectors 33, 32 and 3 in connection. In the container 43 a coil 29 is arranged through which a medium to be cooled can be guided. If necessary, they can also be in the containers 40, 41 and 42 similar helix can be arranged so that the device is at different temperatures Can deliver cold. If necessary, a medium to be cooled can be in thermal contact in sequence be brought with the medium in the containers 40, 41, 42 and 43. The high pressure medium of the Compressor 1 is gradually reduced in pressure in ejectors 31, 32 and 33.

After the ejectors, the medium is collected in the container 40. The steam can come out of this container flow back to the compressor. The liquid in the container 40 is also gradually decreased in pressure, so that in the containers 41, 42 and 43 there is a gradually decreasing pressure. Of the Low pressure steam of containers 41, 42 and 43 becomes

ίο sucked off by the ejectors 33, 32 and 31 and on brought the pressure in the container 40. In this way, there is an extremely simple construction of a Device that can deliver the generated cold at different temperatures. Although in the

is drawing only three ejectors and three additional Containers are shown, it will be apparent that this number can be expanded or decreased as desired can be. It is also possible, as shown in FIG. 3a illustrates a number in series to connect placed ejectors with their suction sides with the same additional container.

Although according to the drawing, the additional containers in a certain order to the relevant Suction sides of the ejectors are connected, this order can of course be changed while the device is still delivering cold.

4 shows schematically a device for generating cold, which contains three ejectors 121, 122 and 123, which are connected with their supply sides 124, 125, 126 to the high pressure part 3 of the heat exchanger. The ejector 121 is connected with its outlet 127 to a container 128 in which a pressure p ₂ prevails. The ejector 122 is connected by its discharge 129 to the container 130 in which a pressure p ₃ prevails. The discharge 131 of the ejector 123 connects to a container 132 in which a pressure p ₄ prevails. The containers 128, 130 and 132 are connected to one another by lines with throttle valves 133 and 134, while the container 132 is connected by a line with a throttle valve 135 to an additional container 136 in which a pressure p ₅ prevails. The vapor space of the containers 136, 132 and 130 is in communication with the suction sides 137, 138 and 139 of the ejectors 123, 122 and 121, respectively. The device also has a number of heat exchangers 140, 141, 142 and 143 in which the various medium flows exchange heat with one another. The vapor space of the container 128 is in communication with the low-pressure part 7 of the heat exchanger. This device thus again comprises a number of containers in which different pressures prevail, so that the cold can again be obtained at different temperatures, if desired. In this device, the ejectors all receive the primary medium under the same pressure P ₁ .

F i g. 5 shows a device for generating cold, in which the compressed and cooled medium from the high pressure part 3 of the heat exchanger is split into two parts. A fitting The selected part is fed to an ejector 60 and the other part to a throttle element 61. The discharge of the ejector and the throttle element open out in the container 62. The vapor space of the container 62 is complete with the inlet 8 of the compressor 1 in communication, while the container further through a throttle member

63 is connected to an additional container 64. In the container 64 there is again a heat exchange coil 29 housed. The vapor space of the container

64 is connected to the suction side 65 of the ejector 60. This ejector sucks out the low-pressure steam the container 64 and brings it to the pressure prevailing in the container 62. A control element 30 provides that the liquid level in the containers 62 and 64 remains constant. In this case it is The pressure ratio between the supply and discharge of the ejector 60 and the throttle element 62 is the same. It is however, it is also possible to connect the discharge of the throttle valve to the container 64 with the lower pressure. This variant is indicated in the drawing with a dashed line.

F i g. 6 shows a device for generating cold in a schematic representation that only contains a container 70 in which the desired low pressure prevails, whichever the temperature corresponds to where the cold is to be delivered. The high pressure part 3 of the heat exchanger closes here to a throttle member 71, in which a part of the compressed medium a throttling process is subjected. The device further includes an ejector 72, the supply 73 of which is connected to the Connects high pressure part of the heat exchanger. The suction side 74 of the ejector is with the vapor space of the container 70 connected. The discharge 75 of the ejector connects to part 7 of the heat exchanger at. The mode of operation of this device results from the preceding explanations.

F i g. 7 shows a device corresponding to that of FIG. 5. However, the ejector 72 is connected to the heat exchanger 3, 7, which means that the steam from the container 70 in part T of the heat exchanger exchanges heat with the medium flowing to the throttle valve 71, whereupon the steam is fed to the suction side 74 of the ejector 72 . The discharge 75 of the ejector 72 connects to a second part 7 ″ of the heat exchanger. The ejector 72 receives the primary medium from a point 76 of part 3 of the heat exchanger.

F i g. Fig. 8 shows an apparatus for generating refrigeration at low temperatures which includes a cold gas refrigerating machine 80 of the multi-room type. This refrigerator includes a compression piston 81 that is movable in a cylinder 82. Furthermore, the cold gas cooling machine contains a displacer which is assembled from two parts 83 and 84 of different diameters. The compression piston 81 and the displacer are movable with a phase difference, changing the volume of a compression space 85 or the expansion spaces 86 and 87. The compression space 85 and the expansion space 86 are in communication with each other through a cooler 88, a regenerator 89 and a first freezer 90. The expansion spaces 86, 87 are connected to one another by a regenerator 91 and a second freezer 92. In operation, the first freezer 90 has a temperature of about 80 ° K, while the second freezer at a temperature of about 15 K ^0.

A compressor 1 compresses a medium, for example helium. The compressed medium first passes a part 3 'of the heat exchanger and then enters a heat exchanger 95 in thermal contact with the first freezer 90. The medium then flows through a part 3 ″ of the heat exchanger and exchanges heat in the heat exchanger 96 with the second freezer 92 , and finally the medium passes a part 3 ′ ″ of a heat exchanger, whereupon the cooled medium is fed to an ejector 21, the discharge of which is connected to a collecting container 23. This collecting container is connected to a container 26 through a line 24 and a throttle element 25 with regulation by a float 97. The vapor space of the container 26 is again connected to the suction side of the ejector 21 through a line 27 with heat exchangers. The vapor space of the container 23 is connected to the inlet 8 of the compressor 1 through the heat exchangers T ", 7" and 7 '. This provides an extremely effective device for generating cold at low temperatures.

F i g. 9 finally shows a device for generating cold at low temperatures, wherein the compressor 1 by a cold gas refrigerator

100, which is provided with a drain valve 101 and an inlet valve 102. The drain valve

101 is designed in such a way that it opens when the pressure in the refrigerator reaches a certain level Has reached a value above the minimum pressure. The refrigerator is thus effective as a compressor while it is also dimensioned such that it also delivers a lot of cold, so that the Medium leaving the cooling machine has a lower temperature than the medium entering.

Although in the illustrated embodiments the device is always a medium or an object cools, a certain amount of liquid can be taken from one of the containers.

The liquid withdrawn from the device must of course be supplemented in the form of gas be fed to the compressor.

The drawing shows the compressor schematically as a single-stage compressor. It will be evident that a multistage compressor may be used. The high pressure medium can also taken from another source and vented the medium at lower pressure.

From the above it can be seen that the invention is a surprisingly effective construction of a Device for generating cold and / or for liquefying gases creates, with the compression member a lower pressure ratio than in the known devices prevails. The energy of the compressed medium is not simply dissipated, but used to remove the steam to bring a container with lower pressure to a higher pressure in which the medium Heat exchanged with a point to be cooled or taken in liquid form of the device will.

The device according to the invention can generate cold at any desired temperature.

For this purpose 2 sheets of drawings

Claims (11)

Patent claims: 1. Device for generating cold and / or for liquefying gases, with a supply for a gaseous medium under high pressure to which the high pressure part is attached at least one countercurrent heat exchanger is connected, in which the under high pressure gaseous medium cools to a temperature which is lower than that mentioned Pressure associated inversion temperature, furthermore with one at the outlet of the high pressure part of the countercurrent heat exchanger containing at least one throttle element Pressure reducing device, as well as with at least one adjoining container, in which brought the medium at lower pressure into thermal contact with a point to be cooled or can be removed from the device in the liquid state, and with a line system, through which the medium of lower pressure via the low pressure part of the counterflow heat exchanger is discharged, characterized in that the pressure reducing device at least one Ejector (21, 31, 123, 60, 72) contains at least part of the still unthrottled cooled Medium high pressure is supplied and its suction side (28, 52, 137, 65, 74) with the Container (26, 43, 136, 64, 70) connected to lower pressure, while the discharge (22, 75) of the ejector is connected to the pipe system through which the medium is lower Pressure is dissipated. 2. Device according to claim 1, which contains at least one compressor, characterized in that that the outlet (2) of the compressor (1) for compressed medium to the supply for the High pressure medium and the pipe system for discharging the medium of lower pressure to the Suction side (8) of the compressor is connected. 3. Apparatus according to claim 1 or 2, characterized in that it has an ejector (21) contains, the supply side (20) to the high pressure part of the heat exchanger (3) and whose discharge side (22) is connected to a collecting container (23), whose steam space with is connected to the pipe system through which the medium at lower pressure is discharged is, and that, preferably with its liquid space, through a line (24) the throttle member (25) with the container (26) is in communication, the vapor space with the Suction side (28) of the ejector is connected (Fig. 2). 4. Apparatus according to claim 1 or 2, characterized in that they have two or more Contains ejectors (121, 122, 123) whose feed sides (124, 125, 126) with the high pressure part of the Heat exchanger (the heat exchanger) and their discharge sides (127, 129, 131) each with one Container (128, 130, 132) are in communication, which gradually lower pressures during operation and are laid in series with one another by lines with throttling elements (133, 134), which lines with the high pressure side preferably into the liquid spaces of the relevant Open container, the container (132) with the lowest pressure through a line with a throttle member (135) with an additional container (136) in communication in which an even lower pressure prevails, and that the vapor space of each container (130, 132, 136) with the exception of the vapor space of the container (128) with the highest pressure, with the suction side (139, 138, 137) of an ejector is connected, the discharge side of which is connected to a container with a higher pressure, while the vapor space of the container (128) with the highest pressure is in connection with the pipe system through which the medium of lower pressure is discharged (Fig. 4). 5. Apparatus according to claim 1 or 2, characterized in that there are several in series contains placed ejectors (31, 32, 33), the discharge side (35, 37) of a preceding ejector cooperates with the feed side (36, 38) of a subsequent ejector, while the Feed side (34) of the first ejector (31) with the high pressure part (3) of the countercurrent heat exchanger and the discharge side (39) of the last ejector (33) is connected to a collecting container (40) is, whose vapor space is in connection with the pipe system through which the medium Lower pressure is discharged, which device also has one or more additional Containers (41, 42, 43) which are connected one behind the other by lines with throttle elements (44, 45, 46) are preferably connected to one another by their liquid spaces, the first additional container (41) is connected to the collecting container (40), while the steam space each of the additional containers with the suction side (50, 51, 52) of one or more of the Ejectors is in connection (F i g. 3, 3 a). 6. Apparatus according to claim 1, 2, 3, 4 or 5, characterized in that it additionally one or more throttle members (61) which are placed in parallel with the ejectors (60) are that part of the medium originating from the high pressure part (3) of the heat exchanger this (s) throttle element (s) passes and then into the collecting container (62) and / or into one of the additional Container (64) arrives (Fig. 5). 7. Device according to one of the preceding claims, characterized in that in the Connection line between the suction side (28) of each of the ejectors (21) and the steam space an associated container (26) contain one or more heat exchangers (110, 111) is (are), in which the medium flowing into the suction side of the ejector carries heat with it Medium of higher pressure exchanged. 8. Device according to one of the preceding claims, characterized in that a Control device (30) is provided, which one or more of the throttle elements (25) in the lines between the liquid spaces of the containers concerned depending on the Regulates the liquid level in these containers. 9. Device according to one or more of the preceding claims, characterized in that that one or more of the mentioned ejectors (21) is (120) controllable (120). 10. Device according to one or more of the preceding claims, characterized in that that a machine (80) is provided for generating cold at low temperatures is, the one or more filled with a working fluid compression (85) and one or more expansion spaces (86, 87) of variable volume, which spaces are in connection with each other and have different temperatures from each other during operation, one or more regenerators being located in the connection between each of these rooms (82, 91), whereby the high-pressure medium that is supplied to the ejector (s) (21) or Throttle element (s) (25, 97) flows in with the working medium in the expansion space (s) is in thermal contact (Fig. 8). 11. The device according to claim 10, characterized in that the machine (100) for generating of cold at low temperatures, possibly together with an additional Compression element as a compressor for the ejector (s) (21) or throttle element (s) flowing into it Medium is used, the machine with a drain (101) and an inlet valve (102) is provided, which is connected to the supply for the high pressure medium or to the line system for Discharge of the medium lower pressure are connected (Fig. 9).